how to scale shared variable deployed on cFP 2120 programatically from a host PC

[MohitMonga]

Hello,

I have a cFP-2120 on which library is deployed. Another library is deployed on my Host PC. Now i am trying to change the scaling of the variable deployed in cFP 2120 through the variable deployed on my host PC in run time. The Variable whose scaling is to be changed is accquiring the field values of AI module on cFP 1800 I/O rack. I don't know exactly the way how to accomplish it. Can some one tell me the right way to change the scaling from Host PC to cFP 2120.

Thanks

Mohit Monga.

[Maurillier]

Hello Mohit,

I assume here that you are changing the scaling of your variable while running the VI. I want to know how you are trying to scale the variable. Are you using property node. If yes, then you have to place the property node inside your RT VI otherwise it won't work. The change in property node in the VI in host PC will not be reflected inside the RT VI.

-Maurillier

[samriddh]

hello,

I am one of the collegeaues of Mohit.

Yes we are using shared variable IO property node of the shared variable and we are doing it programatically in run time. 

We are engaged in designing a SCADA System using LabVIEW which continuously acquires the real time values from sensors who are attached to the cFP Hardware module cFP 1808 IO Rack. 

Initially the signal coming in the range of 4 to 20 mAmps is to be converted to the meaningful information in order to have the status of the physical quantity like change in the Temperature etc. from the PC side.

Both the PC and the cFP 2120 are taking the inputs from the cFP 1808, so it becomes mandatory to scale the coming input signal for having the meaningful information on the Controller too.

Instead of doing Scaling for two times (on Host PC and on the cFP 2120), we decided to run only a single VI of Scaling on the PC side which when called do the scaling of the variables on the PC (Obvious) as well as on the Controller itself.

For doing this the crutial need is to call the controller library in the scaling vi instead to call only one library i.e. PC Library.

It someone changes the scaling of the parameter on the front panel, the change was made to reflect on both of the Library as the names of the variables in both of the libraries are same and there is only one loop in the background on the block diagram which does this in two iterations i.e on zeroth iteration it reflects the change in the PC Library and on first iteration for the Library on the controller Library and saves.

But there is a problem in this, whenever the scaling is changed the same is changed and saved in the controller library which is just residing in the PC and had nothing to do with the controller untill this changed library is deployed on the controller. The previous version of the library is deployed on the controller and it continuously fetches the data.

The changed library is again deployed on the controller for the latest update in the controller variables and i think it needs to be reviewed for any better way of doing the same task (as it was our thought & way of doing this).

On the PC side the changed library is saved and deployed in a sequence of editing and then deploying and is not a big issue.

I had presented the whole pictorial view of the scene and the main reason in the late reply is that we were busy in other couple of tasks.

Hope my explanation had made you familier with the whole scene.

Hoping for an earlier response from your side.

Thanks & Regards,

Samriddh Sarbalhi

[MohitMonga]

Dear,

I was trying to use property node for scaling of the variables on RT target (cFP2120). But the code is unable to run on the same because of that property node. What should i do now?